1 | /*
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2 | * ext_attr.c --- extended attribute blocks
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3 | *
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4 | * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
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5 | *
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6 | * Copyright (C) 2002 Theodore Ts'o.
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7 | *
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8 | * %Begin-Header%
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9 | * This file may be redistributed under the terms of the GNU Public
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10 | * License.
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11 | * %End-Header%
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12 | */
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13 |
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14 | #include <stdio.h>
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15 | #include <unistd.h>
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16 | #include <string.h>
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17 | #include <time.h>
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18 |
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19 | #include "ext2_fs.h"
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20 | #include "ext2_ext_attr.h"
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21 | #include "ext2fs.h"
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22 |
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23 | errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
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24 | {
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25 | errcode_t retval;
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26 |
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27 | retval = io_channel_read_blk(fs->io, block, 1, buf);
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28 | if (retval)
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29 | return retval;
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30 | #if BB_BIG_ENDIAN
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31 | if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
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32 | EXT2_FLAG_SWAP_BYTES_READ)) != 0)
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33 | ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
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34 | #endif
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35 | return 0;
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36 | }
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37 |
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38 | errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
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39 | {
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40 | errcode_t retval;
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41 | char *write_buf;
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42 | char *buf = NULL;
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43 |
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44 | if (BB_BIG_ENDIAN && ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
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45 | (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))) {
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46 | retval = ext2fs_get_mem(fs->blocksize, &buf);
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47 | if (retval)
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48 | return retval;
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49 | write_buf = buf;
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50 | ext2fs_swap_ext_attr(buf, inbuf, fs->blocksize, 1);
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51 | } else
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52 | write_buf = (char *) inbuf;
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53 | retval = io_channel_write_blk(fs->io, block, 1, write_buf);
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54 | if (buf)
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55 | ext2fs_free_mem(&buf);
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56 | if (!retval)
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57 | ext2fs_mark_changed(fs);
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58 | return retval;
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59 | }
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60 |
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61 | /*
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62 | * This function adjusts the reference count of the EA block.
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63 | */
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64 | errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
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65 | char *block_buf, int adjust,
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66 | __u32 *newcount)
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67 | {
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68 | errcode_t retval;
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69 | struct ext2_ext_attr_header *header;
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70 | char *buf = 0;
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71 |
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72 | if ((blk >= fs->super->s_blocks_count) ||
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73 | (blk < fs->super->s_first_data_block))
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74 | return EXT2_ET_BAD_EA_BLOCK_NUM;
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75 |
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76 | if (!block_buf) {
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77 | retval = ext2fs_get_mem(fs->blocksize, &buf);
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78 | if (retval)
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79 | return retval;
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80 | block_buf = buf;
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81 | }
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82 |
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83 | retval = ext2fs_read_ext_attr(fs, blk, block_buf);
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84 | if (retval)
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85 | goto errout;
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86 |
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87 | header = (struct ext2_ext_attr_header *) block_buf;
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88 | header->h_refcount += adjust;
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89 | if (newcount)
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90 | *newcount = header->h_refcount;
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91 |
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92 | retval = ext2fs_write_ext_attr(fs, blk, block_buf);
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93 | if (retval)
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94 | goto errout;
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95 |
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96 | errout:
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97 | if (buf)
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98 | ext2fs_free_mem(&buf);
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99 | return retval;
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100 | }
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